Note that there are two different implementations of POSIX.1
support on VOS. There is an alpha version of POSIX that is
available from the Stratus anonymous ftp site
(ftp://ftp.stratus.com/pub/vos/posix/alpha/alpha.html). There
is a generally-available version of POSIX that comes with the
VOS Standard C compiler and C runtime in VOS Release 14.3.0 or
higher. This port of POSIX will compile and bind with either
version of POSIX.

Most of the Perl features should work on VOS regardless of which
version of POSIX that you are using. However, the alpha version
of POSIX is missing a number of key functions, and therefore any
attempt by perl.pm to call the following unimplemented POSIX
functions will result in an error message and an immediate and
fatal call to the VOS debugger. They are ``dup'', ``fork'', and
``waitpid''. The lack of these functions pretty much prevents you
from starting VOS commands and grabbing their output in perl.
The workaround is to run the commands outside of perl, then have
perl process the output file. These functions are all available
in the generally-available version of POSIX.

Before you can build Perl 5 on VOS, you need to have or acquire the
following additional items.

The VOS Standard C Compiler and Runtime, or the VOS Standard C
Cross-Compiler. This is a standard Stratus product.

Either the VOS OS TCP/IP or STCP product set. If you are
building with the alpha version of POSIX you need the OS
TCP/IP product set. If you are building with the
generally-available version of POSIX you need the STCP
product set. These are standard Stratus products.

Either the alpha or generally-available version of the VOS
POSIX.1 environment.

The generally-available version of POSIX.1 support is
bundled with the VOS Standard C compiler and Runtime (or
Cross-Compiler) in VOS Release 14.3.0 or higher. This is a
standard Stratus product.

You must compile this version of Perl 5 on VOS Release
14.1.0 or higher because some of the perl source files
contain more than 32,767 source lines. Due to VOS
release-compatibility rules, this port of perl may not
execute on VOS Release 12 or earlier.

To build perl 5, change to the ``vos'' subdirectory and type the
command ``compile_perl -processor X'', where X is the processor
type (mc68020, i80860, pa7100, pa8000) that you wish to use.
Note that the generally-available version of POSIX.1 support is
not available for the mc68020 or i80860 processors.

You must have purchased the VOS Standard C Cross Compiler in
order to compile perl for a processor type that is different
from the processor type of the module.

Note that code compiled for the pa7100 processor type can
execute on the PA7100, PA8000, PA8500 and PA8600 processors, and
that code compiled for the pa8000 processor type can execute on
the PA8000, PA8500 and PA8600 processors.

Copy the appropriate version of the perl program module to
this directory. For example, with your current directory
set to the top-level directory of Perl 5, to install the
executable program module for the Motorola 68K
architecture, enter:

!copy_file vos>obj>perl.pm >system>ported>command_library>*

(If you wish to use both Perl version 4 and Perl version 5,
you must give them different names; for example, perl.pm
and perl5.pm).

Create the directory >system>ported>perl>lib.

Copy all of the files and subdirectories from the lib
subdirectory into this new directory. For example, with
the current directory set to the top-level directory of the
perl distribution, enter:

!copy_dir lib >system>ported>perl>lib>5.6

While there are currently no architecture-specific
extensions or modules distributed with perl, the following
directories can be used to hold such files:

If perl is built with the alpha version of VOS POSIX.1 support
and if it attempts to call an unimplemented VOS POSIX.1
function, it will print a fatal error message and enter the VOS
debugger. This error is not recoverable. See vos_dummies.c for
a list of the unimplemented POSIX.1 functions. To see what
functions are unimplemented and what the error message looks
like, compile and execute ``test_vos_dummies.c''.

This port of Perl version 5 to VOS prefers Unix-style,
slash-separated pathnames over VOS-style greater-than-separated
pathnames. VOS-style pathnames should work in most contexts, but
if you have trouble, replace all greater-than characters by slash
characters. Because the slash character is used as a pathname
delimiter, Perl cannot process VOS pathnames containing a slash
character in a directory or file name; these must be renamed.

This port of Perl also uses Unix-epoch date values internally.
As long as you are dealing with ASCII character string
representations of dates, this should not be an issue. The
supported epoch is January 1, 1980 to January 17, 2038.

See the file pod/perlport.pod for more information about the VOS
port of Perl.